GYPSY AND BROWN-TAIL MOTHS AND THEIR CONTROL 31 



particularly in the northern part of the territory, coupled with the 

 work of natural enemies and disease and the continuous repressive 

 measures used in the residential sections, have caused a remarkable 

 decrease in the abundance of this pest. The insect has been found 

 in Nova Scotia and New Brunswick, but has not been reported from 

 there in excessive numbers for several years. 



This pest can easily be shipped on woody plants, but general spread 

 in this manner has been prevented by the strict enforcement of 

 inspection and quarantine regulations. 



LIFE HISTORY 



The different stages in the development of the brown-tail moth are 

 shown in figure 16. 



THE EGGS 



The female moth deposits a small cluster of from 200 to 400 eggs 

 on the underside of a leaf. They are usually laid in July, and are 

 covered with brown hairs from the body of the female. Hatching 

 begins about August 15. 



THE LARVAE 



The newly hatched larvae, or caterpillars, feed on the epidermis of 

 the leaf. After molting once or twice they construct a winter web. 

 This is made by drawing together several terminal leaves and fasten- 

 ing them with silk which they secrete. The larvae from one or more 

 egg clusters live and feed in common, and as cold weather approaches 

 they retire to the web, in which they remain during the winter. In 

 the spring, as soon as the buds begin to develop, the larvae leave the 

 web and feed upon the bud scales and small leaflets. As they increase 

 in size they consume most of the foliage. They become full grown 

 late in June. 



The full-grown larva, which is hairy, is about 1% inches long. The 

 head is light brown. The body is dark brown to almost black, with 

 a broken white line on each side and two conspicuous reddish spots 

 on the dorsum near the posterior end. 



THE PUPAE 



After the caterpillars have finished feeding, they spin loose silken 

 cocoons in which to pupate. These cocoons may be constructed sep- 

 arately, or large numbers may be spun in a single mass. Sometimes 

 leaves are drawn together as shelters; in other cases the cocoons are 

 attached to trees or other objects. About 2 weeks is spent in the 

 pupal stage. 



THE ADULTS 



Emergence of the moths usually begins the first week in July. 

 The adult is pure white, except for the tip of the abdomen, which is 

 covered with brown hairs. The body of the female is much larger 

 than that of the male. These moths are attracted to strong light, 

 and as they fly at night they are often seen around electric lights in 

 cities and towns during the first half of July. 



FOOD PLANTS 



The caterpillars of the brown-tail moth feed on the leaves of apple, 

 pear, cherry, oak, and willow, and they are sometimes found in con- 

 siderable numbers on other common deciduous trees and shrubs. 



